86 THE GEOGRAPHY OF MAMMALS 



inhabited by a considerable number of Mammals which, 

 however, in all probability, also occur on the adjacent 

 mainland. 



The other islands above mentioned, Prince's Island, St. 

 Thomas, and Anno Bon, are all considerably more distant 

 from the coast of Africa, and, so far as we know, do not 

 possess any native Mammals. A certain number of Land- 

 birds have been obtained from these islands, and a few 

 of these are peculiar, but they are all closely allied to 

 forms that occur in the neighbouring West African 

 mainland. 



The most important islands in the Indian Ocean are, 

 apart from Madagascar, Socotra, the Seychelles, the Amir- 

 ante Islands, the Comoros, and finally Reunion, Mauritius, 

 and Rodriguez. 



Socotra is situated about 150 miles due east of Cape 

 Guardafui, the extreme eastern point of Africa. Its fauna 

 and flora were carefully investigated some years ago by 

 Professor Bayley Balfour (1). He found that the only 

 Mammals inhabiting the island are a Bat, which he was 

 unable to obtain, and a Civet (Viverricula), met with 

 also in South Asia, and probably introduced by human 

 agency. 



The Seychelles are distant about 700 miles from the 

 northern point of Madagascar in a north-easterly direction, 

 a more or less continuous chain of islands (Amirante, Provi- 

 dence, and Farquhar) forming a series of stepping-stones 

 between them. But two narrow deep channels of over 1000 

 fathoms run between the Seychelles and Amirante on the 

 one hand, and between Amirante and Providence on the 

 other, thus cutting the Seychelles off from Madagascar by 

 their deep water. 



